Apparatus and methods relating to wavelength conditioning of illumination

ABSTRACT

Lighting systems comprising a spectrum former upstream from a reflective pixelated spatial light modulator (reflective SLM), the SLM reflecting substantially all of the light in the spectrum into at least two different light paths, that do not reflect back to the light source or the spectrum former. At least one of the light paths acts as a projection light path and transmits desired light out of the lighting system. The lighting systems provide virtually any desired color(s) and intensity(s) of light, and avoid overheating problems by deflecting unwanted light and other electromagnetic radiation out of the system or to a heat management system. The systems can be part of another system, a luminaire, or any other suitable light source. The systems can provide virtually any desired light, from the light seen at the break of morning to specialized light for treating cancer or psoriasis, and may change color and intensity at speeds that are perceptually instantaneous.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 10/061,966, filed Jan. 31, 2002, now U.S. Pat. No. 6,781,691,which application claims priority from U.S. provisional patentapplication No. 60/265,991, filed Feb. 2, 2001, and from U.S.provisional patent application No. 60/310,940, filed Aug. 7, 2001.

BACKGROUND

Light bulbs usually provide light that includes all the colors in therainbow: violet, blue, green, yellow, orange, and red. When all of thesecolors are present, the light is known as “white light.” The rainbow,which is the separated colors, is known as a spectrum. Different kindsof light bulbs provide different quantities of the various colors, whichmeans, for example, that some light bulbs provide more red light thanblue light, while other light bulbs provide more green light than orangelight. In addition, most light bulbs also provide light that is notvisible to the naked eye, such as ultraviolet (UV) light and infrared(IR) light.

The different colors of light are known as different wavelengths oflight, and range in the visible spectrum from violet or blue lighthaving a wavelength of about 400 nm to red light having a wavelength ofabout 700 nm; UV light is typically between about 300 nm to 400 nm, andIR light is typically from about 700 nm to 1000 nm.

For a long time, people have wanted to select specific wavelengthsand/or intensities of light for specific situations, such as forlighting a movie scene so that it looks like the middle of a brightsummer day in Mexico City or a cool fall evening with a beautiful sunsetin Anchorage, Ak., for diagnosing or treating disease, for measuring oranalyzing the chemical or physical properties of an object, or forinitiating a physical or chemical change in an object or compound ororganism.

In order to obtain particular wavelengths and intensities of light,movie sets employ highly skilled and specialized lighting techniciansthat use very expensive light bulbs, lighting apparatus, lightingfilters (such as colored “gels”), and the like. The intense heatgenerated by the lights, however, reaches oven-like temperatures and cancook film, filters, and lighting elements. Other situations likewiseemploy expensive personnel and apparatus.

In some previous attempts to deal with these problems, a spectrumformer, such as a prism, has been placed in front of the light bulb toseparate the light beam into its respective wavelengths, then atransmissive pixelated spatial light modulator has been placed in thespectrum. A pixelated spatial light modulator is typically a square orrectangular device (although other shapes are possible) that contains alarge number of tiny pixels and can be turned on or off at will. Turninga line of pixels “on” while turning all others “off” permits the spatiallight modulator to pick a specific color of light; more complex on/offpatterns can pick more complex wavelength and intensity distributions.However, these prior attempts have been problematic because thepixelated spatial light modulators have either absorbed the undesiredlight or reflected it back to the original light source or spectrumformer. In either case, the heat from the undesired light is notdissipated and serious problems may ensue.

Thus, there has gone unmet a need for lighting systems and luminairesthat provide selected light wavelengths and intensities but that do notoverheat, and that can also rapidly switch between different selectedwavelengths or intensities, including highly complex groupings ofwavelengths or intensities. The present invention provides these andother advantages.

SUMMARY

The present invention provides lighting systems that provide virtuallyany desired color(s) and intensity(s) of light, from white light tolight containing only a certain color(s) and intensity(s). The colors,or “spectral output,” which means a particular wavelength, band ofwavelengths, or set of wavelengths, as well as the intensities, whichmeans a “wavelength dependent intensity distribution,” can be combinedand varied as desired. The lighting systems avoid overheating problemsand can be part of other systems or stand alone units such as luminaires(for example, the high-output lighting units used to illuminate moviescenes, concert stages, and night-time construction sites). The systemscan provide any desired light, such as UV light, visible light, andinfrared light.

The lighting systems are a low cost, effective approach to providingcarefully controlled light for a variety of purposes such as medicine,movies, theater, photography, and sports. For example, the light can beselected to substantially mimic light such as high noon in New YorkCity, or the light necessary to diagnose or treat cancer. Additionally,the lighting can be rapidly switched from one desired scenario toanother without moving major parts of the system.

The lighting systems typically comprise a spectrum former upstream froma reflective pixelated spatial light modulator (SLM). The spectrumformer accepts a light beam from a light source and turns it into aspectrum, and the spectrum is then transmitted to the SLM, such as adigital micromirror device (DMD). The SLM reflects substantially all ofthe light impinging on the SLM into at least two different light pathsthat do not reflect back to the light source or the spectrum former. Atleast one of the light paths acts as a projection light path andtransmits desired light out of the lighting system or luminaire. Theother light path can act as a repository for the reflected energy, analternate projection light path, and/or a detection light path wherein adetector measures the light reflected from the pixelated SLM todetermine whether the light has the desired wavelength and intensitycharacteristics. Because the mirrors in the pixelated SLM can be rapidlyswitched back and forth between different light paths, the reflectedlight beam that contains the desired wavelength and intensitydistribution(s) can be alternated back and forth between a projectionlight path and detection light path. If desired, one or more additionalpixelated spatial light modulators can be provided in one or more of thelight paths, to provide further enhanced specificity and preciseness inthe wavelength and intensity distributions or other added benefits.

The pixelated SLM may be operably connected to a controller, whichcontroller contains computer-implemented programming that controls theon/off pattern of the pixels in the pixelated SLM. The controller can belocated in any desired location to the rest of the system. For example,the controller can be either within a housing of the luminaire or it canbe located remotely, connected by a wire, cellular link or radio link tothe rest of the system. If desired, the controller, which is typically asingle computer but can be a plurality of linked computers, a pluralityof unlinked computers, computer chips separate from a full computer orother suitable controller devices, can also contain one or morecomputer-implemented programs that provide specific lightingcharacteristics, i.e., specific desired, selected spectral outputs andwavelength dependent intensities, corresponding to known light sourcessuch as commercial light sources, specific natural lighting situations,such as afternoon at a particular longitude, latitude, time of day andcloudiness, or a specific light for disease diagnosis or treatment, orto invoke disease treatment (for example by activating a drug injectedinto a tumor in an inactive form), or other particular situations.

In one aspect, the present invention provides a lighting system thatprovides a variable selected spectral output and a variable wavelengthdependent intensity distribution. The lighting system comprising a lightpath that comprises: a) a spectrum former able to provide a spectrumfrom a light beam traveling along the light path, and b) a reflectivepixelated spatial light modulator located downstream from and opticallyconnected to the spectrum former, the reflective pixelated spatial lightmodulator reflecting substantially all light impinging on the reflectivepixelated spatial light modulator and switchable to reflect light fromthe light beam between at least first and second reflected light pathsthat do not reflect back to the spectrum former. The reflectivepixelated spatial light modulator can be a digital micromirror device.The reflective pixelated spatial light modulator is operably connectedto at least one controller containing computer-implemented programmingthat controls an on/off pattern of pixels in the reflective pixelatedspatial light modulator to reflect a desired segment of light in thespectrum to the first reflected light path and reflect substantially allother light in the spectrum impinging on the reflective pixelatedspatial light modulator to at least one of the second reflected lightpath and another reflected light path that does not reflect back to thespectrum former, the desired segment of light consisting essentially ofa desired selected spectral output and a desired wavelength dependentintensity distribution.

In some embodiments, the system further comprises a light source locatedupstream from the spectrum former, and the spectrum former comprises atleast one of a prism and a diffraction grating, which can be areflective diffraction grating, transmission diffraction grating,variable wavelength optical filter, or a mosaic optical filter. Thesystem may or may not comprise, between the spectrum former and thereflective pixelated spatial light modulator, an enhancing opticalelement that provides a substantially enhanced image of the spectrumfrom the spectrum former to the reflective pixelated spatial lightmodulator. The reflective pixelated spatial light modulator can be afirst reflective pixelated spatial light modulator, and the desiredsegment of light can be directed to a second reflective pixelatedspatial light modulator operably connected to the same controller oranother controller containing computer-implemented programming thatcontrols an on/off pattern of pixels in the second reflective pixelatedspatial light modulator to reflect the desired segment or other segmentof light in one direction and reflect other light in the spectrum in atleast one other direction. The system can further comprise an opticalprojection device located downstream from the first reflective pixelatedspatial light modulator to project light out of the lighting system as adirected light beam.

The desired segment of light can be selected to substantially mimic aspectral output and a wavelength dependent intensity distribution of atleast one of a known lamp, a cathode ray tube image display device, alight emissive image display device, firelight, candlelight, sunlight orother desired natural ambient lighting scenarios, the output energy fordisease treatment, photodynamic therapy, or disease diagnosis, or toenhance contrast for detection or discrimination of a desired object ina scene.

In another aspect, the present invention provides a stand aloneluminaire sized to project light onto a scene and having a variableselected spectral output and wavelength dependent intensitydistribution. The luminaire can comprise a) a high output light source,b) a spectrum former optically connected to and downstream from thelight source to provide a spectrum from a light beam emitted from thelight source, c) an enhancing optical element connected to anddownstream from the spectrum former that provides an enhanced image ofthe spectrum; d) a reflective pixelated spatial light modulator locateddownstream from and optically connected to the spectrum former, thereflective pixelated spatial light modulator reflecting substantiallyall light impinging on the reflective pixelated spatial light modulatorand switchable between at least first and second reflected light pathsthat do not reflect back to the spectrum former, wherein the reflectivepixelated spatial light modulator can be operably connected to at leastone controller containing computer-implemented programming that controlsan on/off pattern of pixels in the reflective pixelated spatial lightmodulator to reflect a desired segment of light in the spectrum in firstreflected light path and reflect other light in the spectrum to at leastone of the second reflected light path and another reflected light paththat does not reflect back to the spectrum former, the desired segmentof light consisting essentially of a desired selected spectral outputand a desired wavelength dependent intensity distribution; and, e) aprojection system optically connected to and downstream from thereflective pixelated spatial light modulator in the first direction,wherein the projection system projects the desired segment as a directedlight beam to illuminate the scene.

The luminaire can further comprise a detector optically connected to anddownstream from the reflective pixelated spatial light modulator, thedetector also operably connected to a controller containingcomputer-implemented programming able to determine from the detectorwhether the desired segment contains a desired selected spectral outputand a desired wavelength dependent intensity distribution, and adjustthe on/off pattern of pixels in the reflective pixelated spatial lightmodulator to improve the correspondence between the desired segment andthe desired selected spectral output and the desired wavelengthdependent intensity distribution. The luminaire can also comprise a heatremoval element operably connected to the light source to removeundesired energy emitted from the light source toward at least one ofthe reflective pixelated spatial light modulator, the enhancing opticalelement, and the spectrum former. The luminaires and lighting systems,as well as methods, kits, and the like related to them, can furthercomprise various elements that may be specifically discussed for onlyone or the other (for example, the detector of the luminaire is alsosuitable for use with the lighting system).

The heat removal element can be located between the spectrum former andthe first reflective spatial light modulator, between the lamp and thespectrum former, or elsewhere as desired. The heat removal element cancomprise a dichroic mirror. The dichroic mirror can transmits desiredwavelengths and reflects undesired wavelengths, or vice-versa. Theundesired energy can be directed to an energy absorbing surface andthermally conducted to a radiator. The heat removal element can be anoptical cell containing a liquid that absorbs undesired wavelengths andtransmits desired wavelengths. The liquid can be substantially water andcan flow through the optical cell via an inlet port and outlet port in arecirculating path between the optical cell and a reservoir. Therecirculating path and the reservoir can comprise a cooling device,which can be a refrigeration unit, a thermo-electric cooler, or a heatexchanger.

The luminaire further can comprise a spectral recombiner opticallyconnected to and located downstream from the pixelated spatial lightmodulator, which can comprise a prism, a Lambertian optical diffusingelement, a directional light diffuser such as a holographic opticaldiffusing element, a lenslet array, or a rectangular light pipe. In oneembodiment, the spectral recombiner can comprise an operable combinationof a light pipe and at least one of a lenslet array and a holographicoptical diffusing element. The detector can be located in the at leastone other direction, and can comprise at least one of a CCD, a CID, aCMOS, and a photodiode array. The high output light source, the spectrumformer, the enhancing optical element that provides an enhanced image,the reflective pixelated spatial light modulator, and the projectionsystem, can all be located in a single housing, or fewer or moreelements can be located in a single housing.

In a further aspect, the present invention provides methods of lightinga scene comprising: a) directing a light beam along a light path andthrough a spectrum former to provide a spectrum from the light beamtraveling; b) reflecting the spectrum off a reflective pixelated spatiallight modulator that can be operably connected to at least onecontroller containing computer-implemented programming that controls anon/off pattern of pixels in the reflective pixelated spatial lightmodulator, wherein the reflecting can comprise reflecting a desiredsegment of light in the spectrum in a first reflected light path thatcan be not back to the spectrum former and reflecting substantially allother light in the spectrum impinging on the reflective pixelatedspatial light modulator in at least one second reflected light path thatcan be not back to the spectrum former, to provide a modified light beamconsisting essentially of a selected spectral output and a selectedwavelength dependent intensity distribution.

The methods further can comprise emitting the light beam from a lightsource located in a same housing as and upstream from the spectrumformer. The methods further can comprise switching the modified lightbeam between the first reflected light path and the second reflectedlight path. The methods further can comprise passing the light beam byan enhancing optical element between the spectrum former and thereflective pixelated spatial light modulator to provide a substantiallyenhanced image of the spectrum from the spectrum former to thereflective pixelated spatial light modulator. The reflective pixelatedspatial light modulator can be a first reflective pixelated spatiallight modulator, and the methods further can comprise reflecting themodified light beam off a second reflective pixelated spatial lightmodulator operably connected to at least one controller containingcomputer-implemented programming that controls an on/off pattern ofpixels in the second reflective pixelated spatial light modulator toreflect the desired segment of light in one direction and reflect otherlight in the spectrum in at least one other direction.

The methods further can comprise passing the modified light beam by anoptical projection device located downstream from at least one of thefirst reflective pixelated spatial light modulator and the secondreflective pixelated spatial light modulator to project light as adirected light beam.

The methods of lighting a scene can also comprise: a) directing a lightbeam along a light path and through a spectrum former to provide aspectrum from the light beam traveling; and, b) passing the spectrum viaa pixelated spatial light modulator located downstream from andoptically connected to the spectrum former, the pixelated spatial lightmodulator operably connected to at least one controller containingcomputer-implemented programming that controls an on/off pattern ofpixels in the pixelated spatial light modulator, wherein the on/offpattern can be set to pass a desired segment of light in the spectrum inone direction and interrupt other light in the spectrum impinging on thepixelated spatial light modulator, to provide a modified light beamconsisting essentially of a selected spectral output and a selectedwavelength dependent intensity distribution, and wherein the methodsdoes not comprise passing the spectrum by an enhancing optical elementbetween the spectrum former and the pixelated spatial light modulatorthat provides an enhanced image of the spectrum from the spectrum formerto the pixelated spatial light modulator.

In still other aspects, the present invention provides methods ofemitting modified light consisting essentially of a desired selectedspectral output and a desired wavelength dependent intensitydistribution from a stand alone luminaire. The methods can comprise: a)emitting light from a high output light source located in a housing ofthe luminaire; b) passing the light by a spectrum former opticallyconnected to and downstream from the light source to provide a spectrumfrom a light beam emitted from the light source; c) passing the spectrumby an enhancing optical element connected to and downstream from thespectrum former to provide an enhanced image of the spectrum; d)reflecting the spectrum off a reflective pixelated spatial lightmodulator that can be operably connected to at least one controllercontaining computer-implemented programming that controls an on/offpattern of pixels in the reflective pixelated spatial light modulator,wherein the reflecting can comprise reflecting a desired segment oflight in the spectrum in a first reflected light path that can be notback to the spectrum former and reflecting substantially all other lightin the spectrum impinging on the reflective pixelated spatial lightmodulator in at least one second reflected light path that can be notback to the spectrum former, to provide a modified light beam consistingessentially of a selected spectral output and a selected wavelengthdependent intensity distribution; and, e) passing the modified lightbeam by a projection system optically connected to and downstream fromthe reflective pixelated spatial light modulator in the first direction,wherein the projection system projects the modified light beam from theluminaire as a directed light beam.

The methods can further comprise reflecting the desired segment of lightto a detector optically connected to and downstream from the reflectivepixelated spatial light modulator, the detector located in the secondreflected light path or otherwise as desired and operably connected tothe controller, wherein the controller contains computer-implementedprogramming able to determine from the detector whether the desiredsegment contains the desired selected spectral output and the desiredwavelength dependent intensity distribution, and therefrom determiningwhether the first segment contains the desired selected spectral outputand the desired wavelength dependent intensity distribution. The methodscan comprise adjusting the on/off pattern of pixels in the reflectivepixelated spatial light modulator to improve the correspondence betweenthe desired segment and the desired selected spectral output and thedesired wavelength dependent intensity distribution.

The methods can also comprise removing undesired energy emitted from thelight source toward at least one of the reflective pixelated spatiallight modulator, the enhancing optical element, and the spectrum former,the removing effected via a heat removal element operably connected tothe light source. The methods further can comprise a spectral recombineroptically connected to and located downstream from the reflectivepixelated spatial light modulator.

These and other aspects, features and embodiments are set forth withinthis application, including the following Detailed Description andattached drawings. The present invention comprises a variety of aspects,features, and embodiments; such multiple aspects, features andembodiments can be combined and permuted in any desired manner. Inaddition, various references are set forth herein, including in theCross-Reference To Related Applications, that discuss certain apparatus,systems, methods, or other information; all such references areincorporated herein by reference in their entirety and for all theirteachings and disclosures, regardless of where the references may appearin this application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a schematic depiction of a lighting system according toan embodiment comprising a single pixelated SLM.

FIG. 2 provides a schematic depiction of a lighting system according toan embodiment comprising two pixelated SLMs.

FIG. 3 provides a schematic depiction of a lighting system according toan embodiment comprising two pixelated SLMs.

FIG. 4 is a schematic representation of a luminaire comprising a singlepixelated SLM, heat management system and a detector.

FIG. 5 is a graphical representation of an example of selecting adesired wavelength and intensity distribution.

DETAILED DESCRIPTION

The present invention comprises lighting systems comprising a spectrumformer upstream from a reflective pixelated spatial light modulator(SLM), the SLM reflecting substantially all of the light in the spectruminto at least two different light paths, none of which reflect back tothe light source or the spectrum former. At least one of the light pathsacts as a projection light path and transmits desired light out of thelighting system. The lighting systems provide virtually any desiredcolor(s) and intensity(s) of light, and avoid overheating problems bydeflecting unwanted light and other electromagnetic radiation—andtherefore unwanted heat—out of the system or to a heat managementsystem. Thus, the heat is removed from the optical elements of thesystem. The systems can be part of another system, a luminaire, or anyother suitable light source. The systems can provide virtually anydesired light, from the light seen at the break of morning tospecialized light for treating cancer or psoriasis, and may change colorand intensity at speeds that are perceptually instantaneous, for examplein less than a millisecond.

Turning to some general information about light, the energy distributionof light is what determines the nature of its interaction with anobject, compound or organism. A common way to determine the energydistribution of light is to measure the amount or intensity of light atvarious wavelengths to determine the energy distribution or spectrum ofthe light. To make light from a light source useful for a particularpurpose it can be conditioned to remove undesirable wavelengths orintensities, or to enhance the relative amount of desirable wavelengthsor intensities of light.

A high signal to noise ratio and high out of band rejection enhances thesimulation of the spectral characteristics of different light sources orlighting environments, and also enhances fluorescence excitation,spectroscopy or clinical treatments such as photodynamic therapy.

The systems and methods, including kits and the like comprising thesystems or for making or implementing the systems or methods, providethe ability to selectively, and variably, decide which colors, orwavelengths, from a light source will be projected from the system, andhow strong each of the wavelengths will be. The wavelengths can be asingle wavelength, a single band of wavelengths, a group ofwavelengths/wavelength bands, or all the wavelengths in a light beam. Ifthe light comprises a group of wavelengths/wavelengths bands, the groupcan be either continuous or discontinuous. The wavelengths can beattenuated so that the relative level of one wavelength to another canbe increased or decreased (e.g., decreasing the intensity of onewavelength among a group of wavelengths effectively increases the otherwavelengths relative to the decreased wavelength). This is highlyadvantageous because such fine control of spectral output and wavelengthdependant intensity distribution permits a single lighting system toprovide highly specialized light such as light for diagnosing ortreating disease or activating drugs, as well the ability tosubstantially mimic desirable lighting conditions such as a known lamp,a cathode ray tube image display device, a light emissive image displaydevice, a desired natural ambient lighting scenario such as light at aspecific longitude, latitude and weather condition, firelight,candlelight, or sunlight, or other sources of optical radiation.

Definitions.

The following paragraphs provide definitions of some of the terms usedherein. All terms used herein, including those specifically describedbelow in this section, are used in accordance with their ordinarymeanings unless the context or definition indicates otherwise. Alsounless indicated otherwise, except within the claims, the use of “or”includes “and” and vice-versa. Non-limiting terms are not to beconstrued as limiting unless expressly stated (for example, “including”and “comprising” mean “including without limitation” unless expresslystated otherwise).

A “controller” is a device that is capable of controlling a spatiallight modulator, a detector or other elements of the apparatus andmethods herein. A “controller” contains or is linked tocomputer-implemented programming. Typically, a controller comprises oneor more computers or other devices comprising a central processing unit(CPU) and directs other devices to perform certain functions or actions,such as the on/off pattern of the pixels in the pixelated SLM, theon/off status of pixels of a pixelated light detector (such as a chargecoupled device (CCD) or charge injection device (CID)), and/or compiledata obtained from the detector, including using such data to make orreconstruct images or as feedback to control an upstream spatial lightmodulator. A computer comprises an electronic device that can storecoded data and can be set or programmed to perform mathematical orlogical operations at high speed. Controllers are well known in the artand selection of a desirable controller for a particular aspect of thepresent invention is within the scope of the art in view of the presentdisclosure.

A “spatial light modulator” (SLM) is a device that is able toselectively modulate light. The present invention comprises one or morespatial light modulators disposed in the light path of an illuminationsystem. A pixelated spatial light modulator comprises an array ofindividual pixels, which are a plurality of spots that have lightpassing characteristics such that they transmit, reflect or otherwisesend light along a light path, or instead block the light and prevent itor interrupt it from continuing along the light path. Such pixelatedarrays are well known in the art, having also been referred to as amultiple pattern aperture array, and can be formed by an array offerroelectric liquid crystal devices, electrophoretic displays, or byelectrostatic microshutters. See, U.S. Pat. Nos. 5,587,832; 5,121,239;R. Vuelleumier, Novel Electromechanical Microshutter Display Device,Proc. Eurodisplay '84, Display Research Conference September 1984.

A reflective pixelated SLM comprises an array of highly reflectivemirrors that are switchable been at least two different angles ofreflection. One example of a reflective pixelated SLM is a digitalmicromirror device (DMD), as well as other MicroElectroMechanicalStructures (MEMS). DMDs can be obtained from Texas Instruments, Inc.,Dallas, Tex., U.S.A. In this embodiment, the mirrors have three states.In a parked or “0” state, the mirrors parallel the plane of the array,reflecting orthogonal light straight back from the array. In oneenergized state, or a “−10” state, the mirrors fix at −10° relative tothe plane of the array. In a second energized state, or a “+10” state,the mirrors fix at +10° relative to the plane of the array. When amirror is in the “on” position light that strikes that mirror isdirected into the projection light path. When the mirror is in the “off”position light is directed away from the projection light path. On andoff can be selected to correspond to energized or non-energized states,or on and off can be selected to correspond to different energizedstates. If desired, the light directed away from the projection lightpath can also be collected and used for any desired purpose (in otherwords, the DMD can simultaneously cr serially provide two or more usefullight paths). The pattern in the DMD can be configured to produce two ormore spectral and intensity distributions simultaneously or serially,and different portions of the DMD can be used to project or image alongtwo or more different projection light paths.

An “illumination light path” is the light path from a light source to atarget or scene, while a “detection light path” is the light path forlight emanating to a detector. The light includes ultraviolet (UV)light, blue light, visible light, near-infrared (NIR) light and infrared(IR) light.

“Upstream” and “downstream” are used in their traditional sense whereinupstream indicates that a given device is closer to a light source,while downstream indicates that a given object is farther away from alight source.

The scope of the present invention includes both means plus function andstep plus function concepts. However, the terms set forth in thisapplication are not to be interpreted in the claims as indicating a“means plus function” relationship unless the word “means” isspecifically recited in a claim, and are to be interpreted in the claimsas indicating a “means plus function” relationship where the word“means” is specifically recited in a claim. Similarly, the terms setforth in this application are not to be interpreted in method or processclaims as indicating a “step plus function” relationship unless the word“step” is specifically recited in the claims, and are to be interpretedin the claims as indicating a “step plus function” relationship wherethe word “step” is specifically recited in a claim.

Other terms and phrases in this application are defined in accordancewith the above definitions, and in other portions of this application.

Turning to the figures, FIG. 1 schematically depicts a lighting system 2that provides light having a variable, selected spectral output and avariable, selected wavelength dependant intensity distribution. Lightsource 4 is disposed at an upstream end of a light path and emits alight beam 18 that passes by an enhancing optical element 6 comprising afocusing lens 8 and a collimating lens 10. In the embodiment shown, theelements of enhancing optical element 6 are lenses that transmit thelight. Any suitable optical elements that can be employed, such aslenses, mirrors, filters for the forming, mixing, imaging, collimatingor other conditioning of the light that is desired. Thus, the light ispassed by the enhancing optical element 6 either by transmitting thelight or by reflecting the light or otherwise by acting upon the light.If desired, detectors, heat management systems and other desiredelements can also be provided in the primary projection light path,connected by mirrors, lenses or other optical components. However, it isan advantage of the present system that such components need not beplaced in the primary light path unless specifically desired, therebyreducing the noise and interference introduced by the additionalcomponents.

Light beam 18 continues along the light path to spectrum former 12.Spectrum former 12 can be any desired optical element that separates alight beam into its respective spectral components, such as a prism, adiffraction grating, either planar or curved, such as a reflectivediffraction grating or a transmission diffraction grating, an opticalfilter comprising a linearly variable wavelength filter or otherspatially variable wavelength filter, or a mosaic optical filter. Alinearly variable wavelength filter is an optical filter where thewavelength that is transmitted varies across the face of the filter,such as filters made by OCLI, a JDS Uniphase company, where thewavelength of transmission varies in a continuous manner betweenpositions of incident light from one end of the filter to the other end.This filter can be linearly variable, non-linearly variable or step-wisevariable. After light beam 18 passes by spectrum former 12, it continuesalong the light path as spectrum 13. In FIG. 1, red light is depicted atthe lower edge of spectrum 13 while violet light is depicted at theupper edge of spectrum 13. As depicted, spectrum 13 passes bycollimating or focusing optics 14 and then on to a reflective pixelatedSLM 16.

In most embodiments, the spatial light modulator is a reflective spatiallight modulator, not a transmissive spatial modulator such as an LCD orliquid electrophoretic spatial light modulator. In addition, thereflective pixelated SLMs are capable of reflecting the light in aplurality of directions, and, as depicted in FIG. 1 and elsewhereherein, are located or disposed so as to not reflect light back towardeither the spectrum former 12 or the light source 4. For example, thelight can be directed in second reflective light path 15, or, in theembodiment shown, in a third reflective light path 17. This provides asignificant vantage because it dissipates heat and other energyaccompanying the spectrum, such as heat from undesired wavelengths inthe spectrum, heat from additional electromagnetic radiation outside ofthe spectrum, and other undesired energy. If desired, the spectrum canbe selected from among electromagnetic radiation outside of the visiblelight range, although typically the electromagnetic radiation will beselected from among wavelengths that are in or near the visible lightrange (usually ranging from UV light to IR light). The reflectivepixelated SLM 16 can be switched from one light path to another asdesired.

Reflective pixelated SLM 16 is located downstream from and is opticallyconnected to spectrum former 12, which means that reflective pixelatedSLM 16 receives a substantial portion of the spectrum, at least enoughof the spectrum to act on it to provide a desired segment of lightcontaining the desired wavelengths and wavelength intensities. Thus, thereflective pixelated SLM reflects substantially all light impinging onit. Accordingly, reflective pixelated SLM 16 provides a desired segment30 comprising a spectrally selected light beam. Desired segment 30 thenpasses by a light projection optical system 22 which as depicted in FIG.1 comprises a lens 24 and spatial mixing optics 28 and a projection lensor optical system 72 for projection to a target scene 34.

The second, or more, light paths can serve to exhaust unwanted energy,to provide alternate projection light paths, to provide detection lightpaths so that sampling of either the undesired light or the desiredlight can be obtained (the desired segment can be sampled because theon/off status of the pixels in the projection light path can be set tosend the desired segment to the detector for analysis, then switchedback to the projection light path). As depicted for the luminaire inFIG. 4, SLM 16 is operably connected to at least one controller 44 thatcontains computer-implemented programming that controls the on/offpattern of the pixels. The pattern is set to reflect the desired segment30 of the spectrum in the first reflective light path (in FIG. 1, thefirst reflective light path is the same as the projection light path)and then to reflect substantially all other light in the spectrum in atleast one other reflective light path. The desired segment of light thenconsists essentially of a desired selected spectral output and a desiredwavelength dependant intensity distribution. The desired segment can beset to include any desired interference or noise light coming eitherintentionally, from inadequacies in the system such as background noise,or from malfunctions in the system.

FIG. 2 schematically depicts a lighting system 2 according to anotherembodiment. Light source 4 emits light beam 18 that passes by spectrumformer 12 to provide a spectrum 13. In the embodiment in FIG. 2, thesystem does not comprise any enhancing optical element(s) such aslenses, mirrors and the like between either the spectrum former and thereflective pixelated SLM, or between the light source and the spectrumformer. Enhancing optical elements such as lenses, mirrors, and thelike, provide a substantially enhanced image of the spectrum to thereflective pixelated SLM, which means that the spectrum has not beenfocused or otherwise substantially improved by optical elements. In FIG.2, spectrum 13 is reflected off reflective pixelated SLM 16 to providedesired segment 30, then passes by collimating optics 14 and reflectsoff a second reflective pixelated SLM 20. Second reflective pixelatedSLM 20 can be set to have an on/off pattern substantially similar oridentical to the pattern in the first reflective pixelated SLM 16, orotherwise as desired. Although the additional reflection and additionaloptical elements that may be employed may attenuate the overall power ofthe light beam, the non-desired light is significantly greaterattenuated, and thus a very high resolution, high contrast, spectrallyselected beam 32 is provided. This beam can then projected out to atarget 34.

FIG. 3 is similar to FIG. 2 except that certain collimating, focusingand other enhancing optical elements such as elements 6, 8, 10, 14 aredisposed in light beam 18 and spectrum 13, and the system furthercomprises spatial mixing optics 28 that act as an optical projectiondevice to project light out of the lighting system as a directed lightbeam.

FIG. 4 schematically depicts a stand-alone luminaire 40. A stand-aloneluminaire is a lighting device that is mobile and portable, andtypically pointable. In some embodiments, it is an advantage of thepresent luminaires that the light beam from the luminaire can be pointedin different directions without moving the housing 70 of the luminaire40. A stand-alone luminaire is not merely a part of a larger device, forexample it is not a light source in a movie projector, but is rather astand-alone light source such as a spotlight, flashlight or otherindependent light source. The stand-alone luminaire is sized to projectlight onto a scene and thus comprises a high output light source, whichindicates a light source of greater size and intensity (and, therefore,typically greater heat), than a light source that would be used in asmall scientific instrument such as a spectrometer or spectroradiometer.

In FIG. 4, light source 4 emits light that passes by a focusing lens 8,through an aperture 42 and by collimating lens 10. Light beam 18 thenimpinges on a heat management system 50. In the embodiment shown, heatmanagement system 50 comprises a heat trap 48 and a beam splitter 46that eliminates unwanted energy from light beam 18. Heat managementsystems can be located in other desired locations in the luminaire (aswith the lighting systems discussed elsewhere herein), for example inone direction or another of the reflected light paths emanating from thereflective SLM 16. Thus, heat management system 50 removes undesiredenergy emitted from the light source toward at least one of reflectivepixelated SLM 16, the enhancing optical element 6, and spectrum former12. The beam splitter 46 is typically a dichroic mirror and the systemcan be designed such that the dichroic mirror transmits desiredwavelengths and reflects undesired wavelengths or vice-versa. The heattrap 48 can be any suitable heat trap, such as an energy absorbingsurface, preferably one thermally connected to thermally conduct theheat to a radiator, or an optical cell containing a liquid that absorbsundesired wavelengths and transmits desired wavelengths, such as water.For embodiments where the heat trap 48 comprises an optical cell, theoptical cell can also comprise an inlet port and an outlet port so thatfresh liquid can be provided, and if desired the liquid can flow in arecirculating path between the optical cell and a reservoir. There-circulating path or the reservoir can further comprise a coolingdevice such as a refrigeration unit, a thermal-electric cooler and aheat exchanger.

In FIG. 4, The collimated light passing the heat trap is directed towavelength dispersing element 12. The wavelength dispersed beam passingthis element comprises a group of wavelengths, where any givenwavelength in the beam travels a path that is substantially parallel tosimilar wavelengths but varies in angle relative to the optical axis ofthe system, with respect to other wavelengths. Wavelength dispersed beam13 passes by a light focusing lens 52 that focuses the wavelengthdispersed beam into a spread spectrum 54 on the surface of SLM 16.Spread spectrum 54 then reflects off reflective pixelated SLM 16 ineither a first direction 56 or in a second direction 58. Reflectivepixelated SLM 16 is operably connected to a controller 44. Additionaldirections or light paths can be provided if desired. In seconddirection 58, the light is directed to a spectral measuring device 60.Such spectral measuring devices are well known in the art and cancomprise, for example, spectrometers, spectroradiometers, charge coupleddevices (CCDs), charge injection devices (CIDs), a complementarymetal-oxide semi-conductors (CMOSs), photodiode arrays, or any otherdesired spectral measuring devices. As discussed elsewhere, the spectralmeasuring device 60 provides analysis and determination whether eitherdesired segment or any other portion of the spectrum 54 comprises thedesired wavelength(s) and intensity(s).

Spectrally selected beam 68, which comprises the desired segment oflight, passes to a light mixing system 62, which in the embodiment showncomprises a spectral recombiner comprising a directional diffuser, suchas a holographic optical diffuser 64 and a light pipe 66. The spectrallyselected beam 68 then passes by a projection system 72 suitable forprojecting the light to a scene. The light exits the luminaire via apassageway 74 in a single housing 70 that contains the elements ofluminaire 40. Typically, the housing contains at least the light source4, the spectrum former 12, at least a portion of the heat managementsystem 50, the reflective pixelated SLM 16, and the various opticalsystems such as 6, 62, and 72. If desired, the housing can contain allof the elements for the luminaire including controller 44 (which may bea computer chip). The single housing can be unitary or it can be made ofseveral pieces, and it can also be jointed, slitted, or otherwisemodified to suit particular needs. Although a single housing need not beunitary, it is comprised of physically connected elements so that it canbe picked up and carried by a person or other user as a single unit.

FIG. 5 graphically depicts an example where apparatus and methods asdescribed herein are used to provide no spectral conditioning, or toprovide a modified light beam consisting essentially of a selectedspectral output and a selected wavelength depended intensitydistribution. In case 1 in FIG. 5, light from a xenon light source isreflected off a reflective pixelated SLM wherein all the mirrors are inthe “on” state, and thus the output light is substantially identical tothe input light. In case 2, the light from the xenon light source isreflected off a reflective pixelated SLM wherein the on/off pattern ofthe pixels is set to substantially mimic a spectral output of a whiteCathode Ray Tube (CRT) display monitor. Accordingly, the output light ofthe system is also substantially identical to the white CRT pattern. Asnoted elsewhere herein, alternative patterns can be provided in rapidand simple form as desired.

Turning to some of the methods, and as discussed elsewhere herein, themethods include lighting a scene by directing a light beam along a lightpath through a spectrum former, and then reflecting the spectrum off areflective pixelated SLM wherein the reflected light is reflected in afirst reflected light path or in at least one second reflected lightpath that is not back to the spectrum former. This provides a modifiedlight beam comprising a selected spectral output and a selectedwavelength dependant intensity distribution.

The methods can further comprise emitting the light beam from a desiredlight source and switching the modified light beam between one or morereflected light paths. The modified light beam can be passed by a secondspatial light modulator, preferably reflected off a second reflectivepixelated spatial light modulator, to provide a substantially improvedmodified light beam. The methods can additionally comprise passing thelight beam by a variety of alternate optical elements as discussedherein, such as collimating lenses, collimating mirrors, dichroicmirrors, focusing lenses and projection assemblies. The methods furthercomprise algorithms wherein a desired or known illumination scenario isencoded in computer-implemented programming, and then thecomputer-implemented programming controls the on/off pattern of pixelsin the reflective pixelated SLM to provide the desired illumination. Theprogramming can control both the wavelengths that are provided and theintensity of the wavelengths, thus providing precise control of bothcolor, and intensity, sometimes referred to as gray scale, of thevarious components of the illumination. The methods can be applied inlighting systems that are either stand-alone, such as luminaires, orthey are a part of other devices, such as lighting systems andscientific apparatus or in movie projectors.

Turning to some additional general discussion, since the light has beenspectrally dispersed across the reflective pixelated SLM, selectivelyturning on or off individual mirror elements can selectively reflectonly one narrow wavelength of light from the light dispersive element,such as only a pure green line of light in a typical linear spectrum.Non-linear spectra can also be used; if desired, the entirety or anydesired portion of the light can be transmitted to a detector, whichdetector can then determine the wavelength striking the variousdetection elements of the detector, and then provide feedback to thereflective pixelated SLM so that only desired pixels are turned on,which set of pixels can be as complex a shape as desired or needed. Byvarying the duty cycle of certain mirrors in the group to be turned onor off, virtually any spectral distribution of light can be created.

The color control system or detector can include a color responsivefeedback element such as a photodiode array or other suitabletransducer, that is placed in the path of the spectral image projectedtoward the reflective pixelated SLM and near to the reflective pixelatedSLM image. The color control system can measure beam color distributionof the lamp prior to or after color selection. The color control systemmay be placed such that it samples either a portion of the beam thatdoes not strike the reflective pixelated SLM. In one embodiment themeasurement element can be placed in the path of the light that is notpropagated toward the projection optics and the reflective pixelated SLMdevice can select light to be propagated to the measurement device inresponse to system controller signals. This provides feed back signalsto the controller of the reflective dixelated SLM to allow correctionfor lot to lot variation and aging among lamps. This can be used tocolor match among luminaires.

While reflective pixelated SLMs can exhibit high reflectance and canhave a signal to noise ratio of about 1000:1, this may not be sufficientfor some applications. In some embodiments a second reflective pixelatedSLM element can added to the optical path. The selected light from thefirst reflective pixelated SLM is directed to a second reflectivepixelated SLM. Mirrors on the second reflective pixelated SLMilluminated by the selected light direct it to the collection opticalpath. The other mirrors remain in the “off” position, furtherattenuating the out of band light. While the desired output light willbe further attenuated by a percentage of about 10–90%, the out of bandlight will be attenuated by a further factor of 1000, which results in anet increase of the signal to noise ratio.

A lamp is a one type of light source that produces optical energy in theform of light by conversion of electrical or chemical energy. Commontypes of lamps are tungsten filament lamps (Osram-Sylvania) andQuartz-Tungsten-Halogen (QTH) lamps (Gilway Technical Lamp). Preferredsources of illumination have a broad range of energy that is relativelyevenly distributed in the visible spectrum. A preferred lamp is a shortarc xenon lamp with integral reflector such as the Cermax lamp producedby Perkin Elmer. The invention may employ any type of light emittingobject as a light source, providing it encompasses all the wavelengthsdesired after spectral conditioning.

The output of the lamp can focused, spatially mixed, imaged, collimated,spectrally recombined, and projected. The focusing, collimating, spatialmixing, spectrally recombined, or imaging elements can be lenses,mirrors or other elements as desired, and can be placed between thelight source and the wavelength dispersive element or elsewhere in theoptical path as desired in view of the present disclosure. Thewavelength dispersive element spatially disperses the light from thelamp according to energy or wavelength. Light mixing or recombiningsystems can comprise a Lambertian diffuser such as a ground or etchedglass. Lambertian diffusers may be transmissive or reflective and areavailable from companies such as Melles-Griot or Labsphere. Light mixingor recombining systems can also comprise a directional light diffuser,which is a diffusing element that scatters light in a directional mannersuch that the light propagates in a desired direction from the diffuser.One example of a directional light diffuser is a holographic diffuser. Aholographic diffuser is a structured optical element created byholography that can spatially homogenize a beam of light. Holographicdiffusers can be designed to achieve specific forward scattering anglesof light. Holographic diffusers are available from companies such asPhysical Optics Corporation of California. Light mixing systems can alsocomprise a lenslet array. A lenslet array comprises a multiple number oflenses molded or otherwise formed in an optical element in the form ofan array that is closely packed together. The array of lenses may berectangular or hexagonal, fractal or another periodic arrangement oflenses that causes a beam of light to be directed in a way thatspatially homogenizes the light energies in the beam. Another suitablelight mixing system can comprise a light pipe, which can be rectangularin cross-section and may be tapered or not in the direction of lightpropagation. The light pipe can be made of a transmissive material suchas an optical glass with a refractive index that differs from the mediumin which the light pipe is placed, such as air or water, such that totalinternal reflection of the desired wavelengths occurs. Alternatively,the light pipe can have a box-like arrangement of mirrors open atopposite ends that allows light to propagate by reflection from themirrored surface along the axis of the box. Light pipes are typicallyemployed in devices such as digital image projectors. The variouselements can also be combined, for example a holographic diffuser andlight pipe, or a lenslet array and light pipe. The light pipe may havethe diffuser or lenslet array embossed, molded, etched, or cemented onone end of it.

The light path(s) can comprise transmission via an optical fiber oroptical fiber bundle or other desired light guide. A “light guide” is adevice well known in the art, typically flexible, that comprises anouter layer and a light transmissive core that carries light from onelocation to another, such as an optical fiber, liquid light guide orhollow reflective light guide. The outer layer can comprise the outersurface of the same material that makes up the core or can be a separateor additional material. A light guide typically also comprises asubstantially non-light transmissive cladding. A “light guide bundle” isa plurality of such light guides combined into a single strand, and cancomprise a binder or filler material between the individual light guidesof the bundle. Such cladding and filler, as well as anything else thatmay be disposed between the light guide cores of a light guide bundle,can be referred to as an inter-core area.

The ability to precisely select wavelengths for illumination is alsouseful for diagnosing and treating clinical conditions in humans oranimals. Light with an action spectrum that activates a drug used forphotodynamic therapy can be selected with high precision and may be usedin place of some costly light sources such as lasers for someapplications. The ability to switch between various wavelengths and toprecisely control the amount of light delivered enables a wide range oftreatments from a single source.

The ability to precisely select wavelengths for illumination is alsouseful for enhancing the contrast of a desired object in a scene. Such alight source can be used to enhance the detection of an object by directhuman visual inspection, or by using an imaging device such as a camera.Light with a spectrum that enhances contrast may be used in militaryapplications to improve contrast between enemy camouflage andbackground, or to assist in identifying friend and foe. It could also beused to enhance detection of survivors for air-sea rescue,discrimination between types of vegetation, or other objects ofinterest.

From the foregoing, it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the inventionincludes such modifications as well as all permutations and combinationsof the subject matter set forth herein and is not limited except as bythe appended claims.

1. A lighting system that provides a variable selected spectral outputand a variable wavelength dependent intensity distribution, the lightingsystem comprising a light path that comprises: a) a spectrum formerconfigured to provide a spectrum from a light beam traveling along thelight path, and b) a pixelated spatial light modulator locateddownstream from and optically connected to the spectrum former, thepixelated spatial light modulator configured to pass desired light fromthe spectrum to select a segment of light, wherein the pixelated spatiallight modulator is operably connected to at least one controllercontaining computer-implemented programming that controls an on/offpattern of pixels in the pixelated spatial light modulator to provide adesired segment of light comprising the desired spectral and intensitydistribution, the desired segment of light consisting essentially of adesired selected spectral output and a desired wavelength dependentintensity distribution, c) and wherein the pixelated spatial lightmodulator is a first pixelated spatial light modulator, and wherein thedesired segment of light is directed to a second spatial light modulatoroperably connected to at least one controller containingcomputer-implemented programming that controls an on/off pattern ofpixels in the second spatial light modulator to select the desiredsegment.
 2. The lighting system of claim 1 wherein the first pixelatedspatial light modulator and the second pixelated spatial light modulatorare connected to a single controller.
 3. The lighting system of claim 1wherein the desired selected spectral output and desired wavelengthdependent intensity distribution substantially mimic a desired portionof a wavelength dependent distribution of output energy of at least oneof a known lamp, a cathode ray tube image display device, a lightemissive image display device and a source of optical radiation.
 4. Thelighting system of claim 1 wherein the desired selected spectral outputand desired wavelength dependent intensity distribution substantiallymimic a desired wavelength dependent distribution of output energycorresponding to a desired natural ambient lighting scenario.
 5. Thelighting system of claim 1 wherein the desired selected spectral outputand desired wavelength dependent intensity distribution substantiallymimic a desired wavelength dependent distribution of output energy fordisease treatment.
 6. The lighting system of claim 1 wherein the desiredselected spectral output and desired wavelength dependent intensitydistribution substantially mimic a desired wavelength dependentdistribution of output energy for photodynamic therapy.
 7. The lightingsystem of claim 1 wherein the desired selected spectral output anddesired wavelength dependent intensity distribution substantially mimica desired wavelength dependent distribution of output energy for diseasediagnosis.
 8. The lighting system of claim 1 wherein the desired segmentis selected to substantially mimic a spectral output and a wavelengthdependent intensity distribution of output energy that can enhancecontrast for detection or discrimination of a desired object in a scene.9. The lighting system of claim 1 wherein the lighting system furthercomprises a heat removal element operably connected to the light sourceto remove undesired energy emitted from the light source toward at leastone of the reflective pixelated spatial light modulator, the opticalelement, and the spectrum former.
 10. A lighting system that provides avariable selected spectral output and wavelength dependent intensitydistribution, the lighting system comprising a light path thatcomprises: a) a spectrum former configured to provide a spectrum from alight beam traveling along the light path, and b) a pixelated spatiallight modulator located downstream from and optically connected to thespectrum former, the pixelated spatial light modulator configured topass desired light from the spectrum to select a segment of light,wherein the pixelated spatial light modulator is operably connected toat least one controller containing computer-implemented programming thatcontrols an on/off pattern of pixels in the pixelated spatial lightmodulator to provide a desired segment of light comprising the desiredspectral and intensity distribution, the desired segment of lightconsisting essentially of a desired selected spectral output and adesired wavelength dependent intensity distribution, and c) a detectoroperably connected to a controller containing computer-implementedprogramming configured to determine from the detector whether thedesired segment contains a desired selected spectral output and adesired wavelength dependent intensity distribution, and adjust theon/off pattern of pixels in the pixelated spatial light modulator toimprove the correspondence between the desired segment and the desiredselected spectral output and the desired wavelength dependent intensitydistribution.
 11. The lighting system of claim 10 wherein the systemfurther comprises a light source located upstream from the spectrumformer.
 12. The lighting system of claim 10 wherein the pixelatedspatial light modulator is a first pixelated spatial light modulator,and wherein the desired segment of light is directed to a secondpixelated spatial light modulator operably connected to at least onecontroller containing computer-implemented programming that controls theon/off pattern of pixels in the second spatial light modulator to selectthe desired segment.
 13. The lighting system of claim 10 wherein thesystem further comprises an optical projection device located downstreamfrom at least one of the first pixelated spatial light modulator and thesecond pixelated spatial light modulator to project light as a directedlight beam.
 14. The lighting system of claim 10 wherein the desiredselected spectral output and desired wavelength dependent intensitydistribution substantially mimic a desired portion of a wavelengthdependent distribution of output energy of at least one of a known lamp,a cathode ray tube image display device, a light emissive image displaydevice and a source of optical radiation.
 15. The lighting system ofclaim 10 wherein the desired selected spectral output and desiredwavelength dependent intensity distribution substantially mimic adesired wavelength dependent distribution of output energy correspondingto a desired natural ambient lighting scenario.
 16. The lighting systemof claim 10 wherein the desired selected spectral output and desiredwavelength dependent intensity distribution substantially mimic adesired wavelength dependent distribution of output energy for diseasetreatment.
 17. The lighting system of claim 10 wherein the desiredselected spectral output and desired wavelength dependent intensitydistribution substantially mimic a desired wavelength dependentdistribution of output energy for photodynamic therapy.
 18. The lightingsystem of claim 10 wherein the desired selected spectral output anddesired wavelength dependent intensity distribution substantially mimica desired wavelength dependent distribution of output energy for diseasediagnosis.
 19. The lighting system of claim 10 wherein the desiredsegment is selected to substantially mimic a spectral output and awavelength dependent intensity distribution of output energy that canenhance contrast for detection or discrimination of a desired object ina scene.
 20. The lighting system of claim 10 wherein the lighting systemfurther comprises a heat removal element operably connected to the lightsource to remove undesired energy emitted from the light source towardat least one of the reflective pixelated spatial light modulator, theoptical element, and the spectrum former.
 21. A stand alone luminairesized to project light onto a scene and having a variable selectedspectral output and wavelength dependent intensity distribution, theluminaire comprising: a) a high output light source, b) a spectrumformer optically connected to and downstream from the light source toprovide a spectrum from a light beam emitted from the light source, c) apixelated spatial light modulator located downstream from and opticallyconnected to the spectrum former, the pixelated spatial light modulatorconfigured to pass desired light from the spectrum to select a segmentof light, wherein the pixelated spatial light modulator is operablyconnected to at least one controller containing computer-implementedprogramming that controls an on/off pattern of pixels in the pixelatedspatial light modulator to provide a desired segment of light comprisingthe desired spectral and intensity distribution, the desired segment oflight consisting essentially of a desired selected spectral output and adesired wavelength dependent intensity distribution, d) a projectionsystem optically connected to and downstream from the pixelated spatiallight modulator in the first direction, wherein the projection systemprojects the desired segment as a directed light beam to illuminate thescene, and e) a detector optically connected to and downstream from thepixelated spatial light modulator, the detector also operably connectedto a controller containing computer-implemented programming configuredto determine from the detector whether the desired segment contains adesired selected spectral output and a desired wavelength dependentintensity distribution, and adjust the on/off pattern of pixels in thepixelated spatial light modulator to improve the correspondence betweenthe desired segment and the desired selected spectral output and thedesired wavelength dependent intensity distribution.
 22. The luminaireof claim 21 wherein the pixelated spatial light modulator is a firstpixelated spatial light modulator, and wherein the desired segment oflight is directed to a second spatial light modulator operably connectedto at least one controller containing computer-implemented programmingthat controls an on/off pattern of pixels in the second pixelatedspatial light modulator to provide an improved desired selected spectraloutput and desired wavelength dependent intensity distribution in thedesired segment of light.
 23. The luminaire of claim 21 wherein thedesired selected spectral output and desired wavelength dependentintensity distribution substantially mimic a desired portion of awavelength dependent distribution of output energy of at least one of aknown lamp, a cathode ray tube image display device, a light emissiveimage display device and a source of optical radiation.
 24. Theluminaire of claim 21 wherein the desired selected spectral output anddesired wavelength dependent intensity distribution substantially mimica desired wavelength dependent distribution of output energycorresponding to a desired natural ambient lighting scenario.
 25. Theluminaire of claim 21 wherein the desired selected spectral output anddesired wavelength dependent intensity distribution substantially mimica desired wavelength dependent distribution of output energy for diseasetreatment.
 26. The luminaire of claim 21 wherein the desired selectedspectral output and desired wavelength dependent intensity distributionsubstantially mimic a desired wavelength dependent distribution ofoutput energy for photodynamic therapy.
 27. The luminaire of claim 21wherein the desired selected spectral output and desired wavelengthdependent intensity distribution substantially mimic a desiredwavelength dependent distribution of output energy for diseasediagnosis.
 28. The luminaire of claim 21 wherein the desired segment isselected to substantially mimic a spectral output and a wavelengthdependent intensity distribution of output energy that can enhancecontrast for detection or discrimination of a desired object in a scene.29. The luminaire of claim 21 wherein the luminaire further comprises aheat removal element operably connected to the light source to removeundesired energy emitted from the light source toward at least one ofthe reflective pixelated spatial light modulator, the optical element,and the spectrum former.
 30. The luminaire of claim 21 wherein thesystem further comprises a spectral recombiner optically connected toand located downstream from the pixelated spatial light modulator. 31.The luminaire of claim 21 wherein the detector comprises at least one ofa CCD, a CID, a CMOS, and photodiode array.
 32. The luminaire of claim22 wherein the high output light source, the spectrum former, theoptical element that provides an enhanced image, the pixelated spatiallight modulator, and the projection system, are all located in a singlehousing.
 33. A method of lighting a scene comprising: a) directing alight beam along a light path and through a spectrum former to provide aspectrum from the light beam traveling; b) passing the spectrum by apixelated spatial light modulator located downstream from and opticallyconnected to the spectrum former, the pixelated spatial light modulatorconfigured to pass desired light from the spectrum to select a segmentof light, wherein the pixelated spatial light modulator is operablyconnected to at least one controller containing computer-implementedprogramming that controls an on/off pattern of pixels in the pixelatedspatial light modulator to provide a desired segment of light consistingessentially of a desired selected spectral output and a desiredwavelength dependent intensity distribution, c) transmitting the desiredsegment of light to a detector operably connected to a controllercontaining computer-implemented programming configured to determine fromthe detector whether the desired segment contains the desired selectedspectral output and a desired wavelength dependent intensitydistribution, and adjusting the on/off pattern of pixels in thepixelated spatial light modulator to improve the correspondence betweenthe desired segment and the desired selected spectral output and thedesired wavelength dependent intensity distribution.
 34. The method ofclaim 33 wherein the method further comprises emitting the light beamfrom a light source located in a same housing as and upstream from thespectrum former, and wherein the spectrum former comprises at least oneof a prism and a diffraction grating.
 35. The method of claim 33 whereinthe method further comprises passing the light beam by an opticalelement between the spectrum former and the pixelated spatial lightmodulator to provide a substantially enhanced image of the spectrum fromthe spectrum former to the pixelated spatial light modulator.
 36. Themethod of claim 33 wherein the pixelated spatial light modulator is afirst pixelated spatial light modulator, and wherein the method furthercomprises passing the modified light beam by a second reflective spatiallight modulator operably connected to at least one controller containingcomputer-implemented programming that controls an on/off pattern ofpixels in the second pixelated spatial light modulator to select thedesired segment of light.
 37. The method of claim 33 wherein the methodfurther comprises passing the modified light beam by an opticalprojection device located downstream from the pixelated spatial lightmodulator to project light as a directed light beam.
 38. The method ofclaim 33 wherein the desired segment is selected to substantially mimica spectral output and a wavelength dependent intensity distribution ofat least one of a known lamp, a cathode ray tube image display device, alight emissive image display device and a source of optical radiation.39. The method of claim 33 wherein the desired segment is selected tosubstantially mimic a spectral output and a wavelength dependentintensity distribution of output energy corresponding to a desirednatural ambient lighting scenario.
 40. The method of claim 33 whereinthe desired segment is selected to substantially mimic a spectral outputand a wavelength dependent intensity distribution of output energy fordisease treatment.
 41. The method of claim 33 wherein the desiredsegment is selected to substantially mimic a spectral output and awavelength dependent intensity distribution of output energy forphotodynamic therapy.
 42. The method of claim 33 wherein the desiredsegment is selected to substantially mimic a spectral output and awavelength dependent intensity distribution of output energy for diseasediagnosis.
 43. The method of claim 33 wherein the pixelated spatiallight modulator is a digital micromirror device.
 44. A method oflighting a scene comprising: a) directing a light beam along a lightpath and through a spectrum former to provide a spectrum from the lightbeam traveling; and, b) passing the spectrum by a pixelated spatiallight modulator located downstream from and optically connected to thespectrum former, the pixelated spatial light modulator configured topass desired light from the spectrum to select a segment of light,wherein the pixelated spatial light modulator is operably connected toat least one controller containing computer-implemented programming thatcontrols an on/off pattern of pixels in the pixelated spatial lightmodulator to provide a desired segment of light consisting essentiallyof a desired selected spectral output and a desired wavelength dependentintensity distribution, c) wherein the pixelated spatial light modulatoris a first pixelated spatial light modulator, and wherein light from thefirst pixelated spatial light modulator is directed to a second spatiallight modulator operably connected to at least one controller containingcomputer-implemented programming that controls an on/off pattern ofpixels in the second spatial light modulator to select the desiredsegment.
 45. The method of claim 44 wherein the method further comprisesemitting the light beam from a light source located in a same housing asand upstream from the spectrum former, and wherein the spectrum formercomprises at least one of a prism and a diffraction grating.
 46. Themethod of claim 45 wherein the method further comprises an opticalprojection device located downstream from at least one of the firstpixelated spatial light modulator and the second pixelated spatial lightmodulator to project light as a directed light beam.
 47. A method ofemitting modified light consisting essentially of a desired selectedspectral output and a desired wavelength dependent intensitydistribution from a stand alone luminaire, the method comprising: a)emitting light from a high output light source located in a housing ofthe luminaire; b) passing the light by a spectrum former opticallyconnected to and downstream from the light source to provide a spectrumfrom a light beam emitted from the light source; c) passing the spectrumby an optical element connected to and downstream from the spectrumformer to provide an enhanced image of the spectrum; d) passing thespectrum by a pixelated spatial light modulator located downstream fromand optically connected to the spectrum former, the pixelated spatiallight modulator configured to pass desired light from the spectrum toselect a segment of light, wherein the pixelated spatial light modulatoris operably connected to at least one controller containingcomputer-implemented programming that controls an on/off pattern ofpixels in the pixelated spatial light modulator to provide a desiredsegment of light consisting essentially of a desired selected spectraloutput and a desired wavelength dependent intensity distribution, e)passing the modified light beam by a projection system opticallyconnected to and downstream from the pixelated spatial light modulatorin the first direction, wherein the projection system projects themodified light beam from the luminaire as a directed light beam, and f)transmitting the desired segment of light to a detector operablyconnected to a controller containing computer-implemented programmingconfigured to determine from the detector whether the desired segmentcontains the desired selected spectral output and a desired wavelengthdependent intensity distribution, and adjusting the on/off pattern ofpixels in the pixelated spatial light modulator to improve thecorrespondence between the desired segment and the desired selectedspectral output and the desired wavelength dependent intensitydistribution.
 48. The method of claim 47 wherein the method furthercomprises adjusting the on/off pattern of pixels in the pixelatedspatial light modulator to improve the correspondence between thedesired segment and the desired selected spectral output and the desiredwavelength dependent intensity distribution.
 49. The method of claim 47or 48 wherein the method further comprises removing undesired energyemitted from the light source toward at least one of the pixelatedspatial light modulator, the optical element, and the spectrum former,the removing effected via a heat removal element operably connected tothe light source.
 50. The method of claim 47 wherein the pixelatedspatial light modulator is a first pixelated spatial light modulator,and wherein the desired segment is directed to a second spatial lightmodulator operably connected to at least one controller containingcomputer-implemented programming that controls an on/off pattern ofpixels in the second pixelated spatial light modulator to provide animproved desired selected spectral output and desired wavelengthdependent intensity distribution.
 51. The method of claim 47 or 48wherein the desired selected spectral output and desired wavelengthdependent intensity distribution substantially mimic a desired portionof a wavelength dependent distribution of output energy of at least oneof a known lamp, a cathode ray tube image display device, a lightemissive image display device and a source of optical radiation.
 52. Themethod of claim 47 or 48 wherein the desired selected spectral outputand desired wavelength dependent intensity distribution substantiallymimic a desired wavelength dependent distribution of output energycorresponding to a desired natural ambient lighting scenario.
 53. Themethod of claim 47 or 48 wherein the desired selected spectral outputand desired wavelength dependent intensity distribution substantiallymimic a desired wavelength dependent distribution of output energy fordisease treatment.
 54. The method of claim 47 or 48 wherein the desiredselected spectral output and desired wavelength dependent intensitydistribution substantially mimic a desired wavelength dependentdistribution of output energy for photodynamic therapy.
 55. The methodof claim 47 or 48 wherein the desired selected spectral output anddesired wavelength dependent intensity distribution substantially mimica desired wavelength dependent distribution of output energy for diseasediagnosis.
 56. The method of claim 47 or 48 wherein the method furthercomprises passing the desired segment by a spectral recombiner opticallyconnected to and located downstream from the pixelated spatial lightmodulator.